To tell you the truth we are already ranking with our main domain for some of the keywords we are after but we're just trying to speeding things up a bit. We've tried the strategy with exact match domains before for some different keywords and, after just 1 week and like 60 listings in different local business directories, the domains ranked for the exact match keyword somewhere between position 3 and 7. The designs were different though.
As long as we don't have to invest more than the actual domain price and we get about 20 bookings per month for each domain, it still counts as profit.
Well, thank you very much once again for your answer. Your oppinions have been more than helpful for me.
Best regards,
Tiberiu